The author was not comparing the levels of violence, the author was comparing the levels of extremism.

I think this paragraph says it pretty well.

"So, just as Christianity and Islam have their extremist groups doing whatever they please in the name of “the greater good,” so does the hacker community. These people are nothing more than self-absorbed, self-righteous, immature, spoiled rotten, egotistical cyber-bullies. They’re terrorists of the internet... #5.1.2